Prise the clip out of the clips and pull it off the injector. It doesn't need any "force", just watch the clip doesn't ping off over the garage
can't recall the torx size, but it's all you need to remove.
The injectors are usually really tight to get out. The o-rings are assembled dry and stick like sticky things, stuck with sticky stuff.......................
IMO, unless you have a sound reason for removing them, i'd leave them alone. As frustration sets in, the body of the injector usually gets broke.....